This invention relates generally to centrifugal pumps and more particularly to a bearing system for centrifugal pumps handling hot fluids such as a boiler feed pump.
Prior art boiler feed pumps normally contain both a controlled leakage seal system and a separate lubricated bearing system at the driven end of the pump, where the driven shaft of the pump penetrates the pump casing. Generally the controlled leakage seal system is fed cooled fluid, of the same type as handled by the pump, wherein the cooled fluid cools the seal and prevents the hot fluid in the pump from damaging the seal while any cooling fluid that reaches the interior of the pump mixes with the pumped fluid without contamination problems. The separate bearing system is located out of the chamber containing the controlled leakage seal system and is lubricated by a separate oil lubricating system. This arrangement makes the driven end of the pump longer, adding weight to the pump casing and, causing the pump to be more expensive.
The foregoing described problems are known to exist in centrifugal pumps in use today. It is apparent that it would be advantageous to provide an alternative directed to overcoming the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.